In container handling operations such as ship-to-shore movements, e.g., a crane-mounted lifting arrangement is typically used for moving a goods container from ship to shore or vice versa. The lifting arrangement typically comprises an upper structure that is suspended from the crane's lifting cables, the upper structure usually named a head-block. The lower side of the head-block is coupled to a lifting frame that is connectable to a container, the lifting frame usually named a spreader. Mechanical connection between the head-block and the spreader is typically accomplished by means of twistable locking pins, often of a design similar to the twist-locks that are typically used for connecting a spreader to a container by engaging corner fittings which are arranged in the upper four corners of the container.
In operation the spreader requires controlling, such as controlling with respect to twist-lock rotation and shifting between locked and unlocked positions; controlling with respect to extension and retraction of spreader beams to accommodate for containers of different lengths; controlling with respect to the lowering and raising movements of corner guides/flipper arms that aid the operator to align the spreader with a container to be engaged, e.g. These movements may be electrically powered and controlling them requires transfer of working power as well as control signals from the head-block to the spreader.
Electrical power and control signals are typically transferred between head-block and spreader via a disconnectable plug and socket coupling that is manually handled, requiring that an operator enters the lifting arrangement several feet above the ground. This manoeuvre may be hazardous, not the least as weather conditions often makes the metal structures slippery.
There is thus a need and desire for a coupling means configured for electrically connecting a head-block to a spreader in a container-lifting arrangement without requiring manual handling of the plug and socket coupling.